The Security Council been stuck over how to approach Syria for the better part of two years, but if this attack turns out to be as bad as initial reports suggest, the consequence to international diplomacy could be profound.

Here are three big questions that the UN will face in the coming days:

1) After months of negotiations, a UN Weapons inspection team finally landed in Syria on Monday. They will almost certainly request access to the site. What happens if the Syrian government simply says, “no?”

2) The Security Council will hold an emergency meeting today. I doubt there will be any formal outcome from this meeting, which will likely involve UN officials telling the council what they know — and what they don’t know — about this incident. However, if it becomes abundantly clear that chemical weapons were used on this kind of scale the key question for international diplomacy is what effect that might have on Russia’s staunch defense of the Syrian government? Will Assad finally have crossed a line that Moscow is not willing to cross?

3) If this does cause a re-evaluation of Russia’s defense of the Assad government, what options might the Security Council pursue? Would it consider international sanctions against members of the Syrian government? A referral to the International Criminal Court? De-recognizing the current government as the legitimate representatives of the Syrian people? Would it go the full Libya and invoke r2p to authorize “all necessary means” to enforce a no fly zone?